Color wheels using colorspace::hcl by luminance

hcl_color_wheels

library(colorspace)

polar2cart <- function(r, theta)   # polar to cartesian coords
{
  rad <- theta * pi /180
  cbind(x = r*cos(rad),
        y = r*sin(rad))
}

h <- seq(0, 360, len=150)     # hue values
c <- seq(0, 100, len=100)     # chroma
p <- expand.grid(h=h,c=c)
xy <- polar2cart(p$c, p$h)

color_wheel <- function(l=50) 
{
  col <- hcl(p$h, p$c, l)
  plot(xy, pch=16, col=col, asp=1, axes=F, 
       main=paste("luminance:", round(l)), 
       xlab="", ylab="")
}

par(mfrow=c(2,2))
for (l in seq(0, 100, len=4))
  color_wheel(l)